Docs: mark PoC features as deprecated (unified ops are default)

- mir_typeop_poc / mir_refbarrier_unify_poc are no-op now; Builder emits
  TypeOp/WeakRef/Barrier by default; Optimizer normalizes legacy ops.
- Update CURRENT_TASK and architecture/proposal docs accordingly.

docs/development/current/CURRENT_TASK.md

@@ -282,7 +282,7 @@ nyash --backend vm local_tests/and_or_truthy_vm.nyash  # 期待: false,true,fals
    - プリンタ拡張: `TypeOp/WeakRef/Barrier` を `--mir-verbose` に明示表示
    - スナップショット整備: 代表ケースで flag ON/OFF のMIR差分固定化
    - vm-stats差分: `weak_field_poc.nyash` 等で JSON 取得・比較（キー: TypeOp/WeakRef/Barrier）
-   - 旗: `mir_typeop_poc`（TypeCheck/Cast→TypeOp）、`mir_refbarrier_unify_poc`（Weak*/Barrier→統合）
+- 注: `mir_typeop_poc` / `mir_refbarrier_unify_poc` は非推奨（no-op）。Builderは統合命令（TypeOp/WeakRef/Barrier）を常に生成する。Optimizerに旧命令→統合命令の正規化パスあり。
 
 2) Builder適用拡大（短期〜中期）
    - 言語 `is/as` 導線（最小でも擬似ノード）→ `emit_type_check/emit_cast` へ配線

docs/development/proposals/mir-typeop-weakref-barrier-poc.md

@@ -17,8 +17,12 @@ Last Updated: 2025-08-23
 - Remove legacy instructions permanently (kept behind feature flags)
 
 ## Feature Flags (Cargo)
-- `mir_typeop_poc`: enable TypeOp and map TypeCheck/Cast to it during build
-- `mir_refbarrier_unify_poc`: enable WeakRef/Barrier unified ops and map legacy calls
+Note: 2025-08 Phase 9.78h 時点で統合命令はデフォルトとなり、以下のflagsは非推奨（no-op）だよ：
+
+- `mir_typeop_poc`: Builderは常に`TypeOp(Check/Cast)`を生成（旧`TypeCheck/Cast`は使わない）。
+- `mir_refbarrier_unify_poc`: Builderは常に`WeakRef/Barrier`を生成（旧`WeakNew/WeakLoad/BarrierRead/Write`は使わない）。
+
+互換性のため、Optimizerに旧命令→統合命令への正規化パス（Pass 0）が入っているにゃ。
 
 ## Mapping (Current → PoC)
 - TypeCheck { value, expected_type } → TypeOp { op: Check, value, type } (bool)
@@ -78,4 +82,3 @@ Last Updated: 2025-08-23
 - Add builder mapping behind flags
 - Add VM execution behind flags
 - Gate CI job to run PoC flags on Linux
-

docs/reference/architecture/mir-26-instruction-diet.md

@@ -87,8 +87,10 @@ Appendix: Rationale
 ---
 
 Feature Flags (Cargo)
-- `mir_typeop_poc`: enable TypeOp PoC mapping (builder emits TypeOp instead of TypeCheck/Cast)
-- `mir_refbarrier_unify_poc`: enable WeakRef/Barrier PoC mapping (builder emits unified ops)
+- Deprecated flags (unified by default):
+  - `mir_typeop_poc`: no-op now. Builder always emits `TypeOp(Check/Cast)` instead of legacy `TypeCheck/Cast`。
+  - `mir_refbarrier_unify_poc`: no-op now. Builder always emits `WeakRef/Barrier` instead of legacy `WeakNew/WeakLoad/BarrierRead/Write`。
+  - Optimizer has a Pass 0 that normalizes any残存の旧命令 → 統合命令（安全ネット）。
 
 Status (2025-08-23)
 - Flags declared in `Cargo.toml` (off by default)